two clusters joined to same storage

[deepak bajpai_2]

I am new to the filed of SAN and have a SAN setup having :
1 MSA 1000
1 2/16 EL fiber switch
2 clusters of Proliant DL 380 G3 servers- Each cluster is single path, 4 node(Windows 2003 Enterprise Edition).

Now, could any body guide me as to how should I configure the storage,switch to securely use two clusters with One storage.

I would like to know the steps to be taken with respect to LUN masking, zoning etc.

If we do LUN masking then do we have to do zoning? If yes then what kind of zoning- hard or soft?


Thanks,
Deepak

[Doug de Werd]

you can use zoning to separate the 2 clusters. see the zoning docs (at the bottom) of this link

http://h20000.www2.hp.com/bizsupport/TechSupport/DocumentIndex.jsp?locale=en_US&contentType=SupportManual&docIndexId=1255&prodTypeId=12169&prodSeriesId=315094

You can also use Selective Storage Presentation (SSP, aka LUN Masking). You set this up using the Array Config Utility (ACU). Once you have created the arrays and volumes on the shared storage, use the ACU to configure SSP so that ALL servers in a cluster can see ALL disks that will be in that cluster. Then do the same for the second cluster. Make sure that every servers in cluster 1 has access to every disk volume in cluster 1, but none of the serevrs in cluster 1 should have access to any of the disks in serevr 2 (and vice versa).

For sure you must configure SSP, and I would do zonign as well.

Thanks,
Doug

[deepak bajpai_2]

Take the scenario.

we have to form 8 logical drives out of 4 physical drives in an Array.

Then using SSP we give exclusive access to 4 Logical drives to cluster1 and other 4 logical drives to cluster2.But, all these 8 logical drives divided between 2 clusters are on same 4 physical drives.

So, can we share same 4 physical disks in one array between two clusters though we have maksed the LUNs formed on them for the two clusters?

Or we have to form a different array for the second cluster?

Thanks,
Deepak

[Greg Carlson]

You could have all logical drives on one array and share the logical drives between the two clusters. I would recommend having each cluster on its on array however.

Ciao,
Greg

[deepak bajpai_2]

But, If one is having a limited storage as we have then we can not limit one array per cluster.

What if we are going to form 6-8 clusters using one MSA 1000 and most of the nodes are 4 and 8 node clusters.

What are the implications of having the same array for 2 or more clusters?

Thanks,
Deepak

[Andrew_168]

Hi,

With regard to your last comment, what you propose is not supported. Please refer to this link.

http://h200005.www2.hp.com/bc/docs/support/SupportManual/c00222327/c00222327.pdf

Regards.

Andy

[Doug de Werd]

As Andy mentioned, you need to pay attention to the cluster maximum limits listed in the link he provided. Th maximum number of total nodes - regardless of the number of individual clusters - that you can attach to a single MSA1000 is 20. And the maximum number of clusters is either 5 2-node clusters, or 4 clusters of 2 or more nodes.

Also, as Greg mentioned, you should really try to separate each cluster's shared disk by physical array. It's OK to have multiple volumes within a physical array, but I would configure them all to the same cluster. SSP will allow you to configure volumes within a physical array to different clusters, but this is not a recommended practice.

Thanks,
Doug